hi i have a 2003 deville i have filled up the coolant numerous times and my coolant keeps disapearing i can smell antifreeze in engine compartment but cant find a leak anybody know what could be causing that? a guy told me to get rid of it because its gonna cost me $6000 to fix it somebody please help just bought the car

I had the same problem with my 01 Seville when I bought it. There was a slow leak; I could smell the fluid from the engine compartment, but not from the exhaust pipe; and, like yours, there was no obvious drip.

What worked for me was to flush the radiator, add new Prestone Dex-Cool antifreeze coolant at a 50% ratio with clean water, and the most important part: follow the Cadillac service manual instructions and add three cooling system seal tabs GM part number 3634621 to the lower radiator hose. They are brown discs about an inch in diameter, 3/4" tall, and you can put them in whole.

I understand that other manufacturers make a similar vegetable based product. The GM packaged product includes 6 tabs with a net weight of 2.12 oz and contains: Ginger, Almond Shell, Sodium Carbonate-CAS #497-19-8, 1,6-Heptadiene-3,5-dione, 1,7-Bis(4-hydroxy-3-methoxyphenyl)-CAS #458-37-7.

Water pump housing / crossover to block gaskets are a common cause of the "mystery" leak. You will likely need to get car high off the ground to find leak. Many shops will do pressure test for coolant leaks for under 30.00.

I have not heard that, 2 tabs for all but 4.1-4.9L (push rod engine) which is 6. NO TABS FOR DIESEL! Info out years ago was anytime coolant is drained tabs should be added to seal minor leaks and extend water pump life.

The 2001 Seville SLS and STS factory service manual calls for DEX-COOL and three pellets of the engine coolant supplement in the lower radiator hose when changing coolant. Changing the fluid and adding the pellets stopped the leak on my car.

Hi all, I just replaced the radiator in my 91 Deville 4.9l and didn't know about these "pellets" that are to be placed in the lower hose. My daughter drove the car approx 100 mi and it leaked like a sieve...her mother was with her and fortunately knew not to let it overheat...long story short, they got it home after stopping and refilling the radiator a few times but her father said it's leaking from the freeze plugs which I have not confirmed. My question is, how many pellets do I need and do I have to go to a Cad dealer to get them? Also, is there a special antifreeze that needs to be used also? Thanks in advance! Darren

Hi all, I just replaced the radiator in my 91 Deville 4.9l and didn't know about these "pellets" that are to be placed in the lower hose. My daughter drove the car approx 100 mi and it leaked like a sieve...her mother was with her and fortunately knew not to let it overheat...long story short, they got it home after stopping and refilling the radiator a few times but her father said it's leaking from the freeze plugs which I have not confirmed. My question is, how many pellets do I need and do I have to go to a Cad dealer to get them? Also, is there a special antifreeze that needs to be used also? Thanks in advance! Darren

that is a different problem .. have your cooling system checked.
the pellets are not meant to stop leakage of such proportions.

Heya Stomper, thanks for the timely reply, muy appreciated...I haven't had a chance to look at it yet, but one thing I know from having been married to that gal for nearly 20 years is she has occasion to participate in hyperbole but certainly if it IS leaking that much...I will be having it checked-out by a mechanic...thanks again!